Burner monitor and control

ABSTRACT

A monitoring and control apparatus ( 220 ) adapted to monitor the combustion of each individual burner ( 224 ) in a furnace ( 1 ). It includes at least one laser ( 221 ) for providing a beam ( 223 ) through a flame of a burner ( 224 ) in a furnace ( 1 ), and at least one detector ( 222 ) for detecting the beams ( 223 ) after they pass through/near the flame. The monitored signal is passed to an electronics unit ( 215 ) that calculates optimum conditions for this burner ( 224 ). The electronics unit ( 215 ) then causes control unit ( 214 ) to adjust the fuel, primary air and secondary air feeds each individual burner ( 224 ) to result in a more efficient system that reduces the amount of emissions released.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to co-pending U.S. Patent Applicationentitled “OPTICAL FLUE GAS MONITOR AND CONTROL” by the same inventor,Michael Tanca, filed on the same day as the present application. Thisapplication incorporates the above-referenced application as if it wereset forth in its entirety herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to coal-fired combustion systems, and moreparticularly to a combustion monitoring system for accurate estimationsof system performance of coal-fired combustion systems.

2. Description of the Related Art

In various coal-fired combustion systems, combustion within a combustionsystem is monitored by a measurement device located in the rear of thefurnace. Typically, this is an oxygen sensor. This measurement deviceprovides feedback signals that are used to control the combustion withinthe combustion system. While such systems work well for controllingaggregate combustion in the furnace, such systems are not responsive tomonitoring and controlling the combustion at different burners withinthe combustion chamber. Therefore, some burners may be working at anoptimum level, with one or more performing poorly. This would result inless than optimum performance. It would be advantageous to identify aspecific burner or location within the combustion chamber that is notoperating well, and only adjust the devices pertaining to that location.

Additional measurement devices provide additional performance, however,it is not feasible to have a large number of measurement devices withina combustion chamber. It is difficult to measure the performance of anindividual burner.

In addition, poor control may result from poor sensitivity of themeasurement devices. It would be advantageous to have more accuratemeasurement devices.

Thus, what are needed are methods and apparatus for accuratemeasurements of individual burners throughout a sampling zone associatedwith a boiler combustion system. Preferably, the measurements providefor improved control thus leading to improved efficiency.

BRIEF SUMMARY OF THE INVENTION

A burner efficiency system (200) is described for adjusting theoperation of individual burner (224) of a tangentially fired furnace(1).

It includes a detector (222) adapted to receive an optical beam (223)and provide an electrical signal corresponding to the optical beam (223)received.

It includes an optical source (221) positioned to create the opticalbeam (223) that passes through a sampling zone (8) and crosses atrajectory (42) just above of a flame emanating from an individualburner (224) and impinges upon the detector (223).

An electronics unit (214) is adapted to receive the signal created bythe detector (222) and identify at least one physical property ofmaterial between the optical source (221) and detector (222). Theelectronics unit (214) creates an adjustment signal indicatingparameters of the individual burner that should be adjusted to optimizethe operation of this individual burner (224).

Some of the parameters that may be adjusted are secondary airflow rateinto the furnace (1), primary airflow rate into the furnace (1), andfuel flow rate into the furnace (1).

It may also be embodied as an apparatus (200) for monitoring a propertyof at least one constituent in flue gas from a furnace (1), theapparatus having an optical monitoring system (220) comprising at leastone optical source (221) adapted to provide an optical beam (223)through flue gasses substantially produced by a single burner (224) of afurnace (1).

It includes at least one detector (222) adapted to detect the opticalbeam (223) and provide a monitored signal to an electronics unit (215).The electronics unit (215) configured to estimate a property of at leastone constituent in the sampling zone and create an adjustment signal toadjust the operation of said furnace (1).

It may be further embodied as a method for adjusting the operation ofindividual burner (224) of a tangentially fired furnace (1). The stepsinclude creating an optical beam (223) that passes through a samplingzone (8) and crosses a trajectory (42) of a flame emanating from anindividual burner (224) and impinges upon a detector (223).

The optical beam (223) is sensed at the detector to create an electricalsignal corresponding to the optical beam (223) received.

At least one physical property of material in the sampling zone (8) isidentified from the created electrical signal.

The identified physical properties are compared to a predetermineddesired level.

Adjustments to a set of burner parameters are calculated from thecomparison that would cause the identified physical property to adjusttoward the predetermined desired level.

The burner parameters of the individual burner are adjusted according tothe calculated adjustments to optimize the operation of the individualburner (224).

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter which is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other features and advantages ofthe invention are apparent from the following detailed description takenin conjunction with the accompanying drawings in which:

FIG. 1 depicts a cross-sectional schematic diagram of a prior artfurnace;

FIG. 2 depicts a plan view of prior art combustion monitoring system;

FIG. 3 depicts a cross-sectional schematic diagram of an embodiment of afurnace according to the present invention;

FIG. 4 depicts a plan view of an embodiment of a combustion monitoringsystem according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Disclosed is a method and apparatus for providing for accuratemonitoring of combustion conditions, flue gas constituents from acombustion system and controlling the combustion system based upon themonitoring. In various non-limiting embodiments provided herein, thecombustion system is a solid fuel, gaseous or liquid fuel firedcombustion system. The combustion system may be a combination furnaceand boiler, or steam generator. One skilled in the art will recognize,however, that the embodiments provided are merely illustrative and arenot limiting of the invention.

The methods and apparatus make use of optical detection systems. Asprovided herein, the optical signaling and detection systems are simplyreferred to as a “monitoring system.” In general, the monitoring systemincludes a variety of components for performing a variety of associatedfunctions. The components may include a plurality of lasers, a pluralityof sensors, a control unit, computer components, software (i.e., machineexecutable instructions stored on machine readable media), signalingdevices, motor operated controls, at least one power supply and othersuch components. The monitoring system provides for a plurality ofmeasurements of at least one gas constituent relative to a samplingzone. The plurality of measurements provide for, among other things,measurement of gas constituents in the sampling zone, such as inrelation to a burner (i.e., a nozzle). The measurements may be performedin multiple locations by use of laser technology, thus providing alocalized, more responsive measure of fuel combustion. Of course, themonitoring system may also be viewed as a control system. Morespecifically, measurement data from the monitoring system may be used tocontrol aspects of the combustion system. Accordingly, for at least thisreason, the monitoring system may be considered as a control system orat least as a part of a control system.

Turning now to FIG. 1, there is shown a side view of a prior art furnace1. The furnace 1 includes a monitoring system 120. In this rudimentaryexample, the monitoring system 120 includes a plurality of opticalsources 121 which may be lasers. The optical sources 121 provide opticalbeams 123 which are detected by a corresponding plurality of detectors122. The detectors 122 are coupled to an electronics unit 115 to providefor characterization of received optical signals. The electronics unit115 provides for estimations of physical aspects of the sampling zone 8between the optical sources 121 and the corresponding detector 122.These physical aspects may include composition or abundance of gasconstituents. The estimations may be performed using techniques as areknown in the art.

Turning to FIG. 2, further aspects of a prior art monitoring system 120are shown. In this example, the monitoring system 120 has a plurality ofoptical sources 121 and a plurality of detectors 122. The opticalsources 121 form a grid of optical beams 123. The optical beams 123 aredetected by the detectors 122. The optical beams 123 are aligned in agrid pattern with intersecting beams as shown. Each of the burners 124are downstream of the fuel feed, primary air feed and secondary air feed(105, 106, 107, respectively of FIG. 1) and provide a mixture of fueland air to the combustion chamber (2 of FIG. 1).

The term “sampling zone” 8 refers to portion of a combustion chamber 2monitored by the monitoring system 120.

The prior art arrangement shown in FIG. 2, show a plurality ofwall-mounted burners 24 which provide combustion in a grid arrangementas depicted. Similarly, a plurality of lasers 121 and detectors 122 arearranged in a similar fashion. Since the flames of each nozzle 24overlap, the detector system 120, cannot detect the functioning of eachindividual burner 24. Therefore, any adjustments must be made on theoverall system, affecting all burners 24. There is no ability to monitorand adjust individual burners 24.

FIG. 3 depicts a cross-sectional schematic diagram of an embodiment of afurnace 1 according to the present invention. The furnace 1 includes aplurality of monitoring systems 220, each for monitoring an individualburner 224, as opposed to the prior art.

It also includes a plurality of control units 224 which control thesecondary air feed 207, and optionally, the fuel feed 205 and theprimary air feed 206 for each individual burner 224, as opposed to theprior art.

Each monitoring system 220 includes at least one optical source 221which may be a laser. The optical sources 221 provide optical beams 223which are detected by a corresponding plurality of detectors 222. Eachbeam passes through a single burner flame or just above a flame tominimize optical scattering, indicated by a trajectory (42 of FIG. 4).Please note that beam 223 passes through the burner flame at an obliqueangle that is difficult to depict in this elevational view.

Solid coal particles are being blown out of the burners 224 whichquickly burn into gases inside of the combustion chamber. These coalparticles scatter and weaken the optical beam 223 resulting ininsufficient intensity being received by the detector 222. In this case,the optical beam 223 and detector 222 must be located just above theflame trajectory 42 where the coal particles are no longer present. Thisprovides a sufficient beam 223 that now can be detected at the detector222 after it intersects flame trajectory 42 at point 45. In this case,it is above the flame.

Please note that the optical beam 223 may be adjusted by adjustingoptical source 221 and detectors 222 such that beam 223 passes throughsampling region 8 and passes through flame trajectory 42 at point 45.Flame trajectory 42 may pass through the flame emitted from the burner224 or may pass slightly above this flame such that most of the solidcoal particles are burned off at that location.

The locations of any of the detector 222 and optical source 221 pairsare interchangeable to allow them to be located on either end of beam223.

Each detector 222 is coupled to its corresponding electronics unit 215to provide for characterization of received optical signals for eachburner 224. Each electronics unit 215 provides for estimations ofphysical aspects of the sampling zone 8 between the optical sources 221and the corresponding detector 222. These physical aspects may includecomposition or abundance of gas constituents. The estimations may beperformed using signal attenuation, signal absorption, fluorescence andother forms of wavelength shifting, scatter and other such techniques.

Even though only a single burner 224, optical source 221 and detector222 are shown here, it is to be understood that there may be multipleburners 224, optical sources 221 and detectors 222 at various levels ofthe furnace 1. These may also be arranged obliquely with reference to ahorizontal and/or vertical axis, and the burners need not be arranged ingroups.

FIG. 4 shows one embodiment of the present invention adapted to atangentially-fired furnace 1 having the plurality of burners 224 locatedat the periphery of the combustion chamber 2. Each burner 224 is aimedtoward a periphery of an imaginary circle where a fireball 9 will occuronce combustion begins. This design causes a fireball 9 to be createdhaving a circular swirling pattern, as is typical for tangentially-firedfurnaces.

For a least one burner 224, the optical source 222 is aimed such thatits beam 223 crosses a single flame trajectory 42 at a point 45. Thelaser beam 223 is monitored by a detector 223 to measure absorption andtransmission at various wavelengths. This allows an analysis of variousgas species and temperatures at the intersection point 45 of the flamefrom a single burner 224.

The point 45 where the flame trajectory 42 crosses the beam 223 shouldbe equal for all burners 224 for accurate, comparable measurements.

By providing such a setup at each of the burners 224, a combustionmonitoring system 220 may be constructed.

Point 45 monitored is the same distance from the burner 224 for allburners 224. Since the flame trajectory 42 is uninterrupted orcontaminated by another lateral burner 224 at a given level, thisgeometry provides independent measurement of the functioning of eachburner 224. There is no external measurement from other burner flamesfrom each reading. This provides a more accurate measurement of eachindividual burner 224.

In this example, beams 223 can be located at the level of the burners224 or slightly above or below the burner 224 to give the strongestdiscrimination of gas species measurement by optical sources 221.

As indicated above the optical sources 221, detectors 222 and beams 223may be adjusted to optimize the readings. They also may be angled upwardor downward, or have adjustable means for modifying their angles.

The present invention provides for measurement and assessment of gasspecies such as CO, CO₂ and O₂ an unburned fuel present in thecombustion chamber 2. Optionally, it may also detect a number of otherentities, such as SO₂, SO₃, NO₂, NO₃ and Hg.

Referring now to both FIGS. 3 and 4, the monitored signal from eachdetector 222 may then be fed back to the electronics unit 215 tocalculate optimum fuel, primary airflow and secondary air flow. This isfed to the control unit 214 of each burner 224 to control the fuel flow205, primary air feed 206, and secondary air feed 207. These may beregulated with common devices such as air dampeners, valves and otherflow controls.

For convenience of explanation, the monitoring system 220 may beregarded as producing “measurement data,” “monitoring data,”“characterization data” and the like. The combination of the monitoringsystem 220 and the control unit 214 results in a monitoring and controlsystem 200.

Having thus described aspects of the monitoring and control system 200,one skilled in the art will recognize that features of merit in theinvention include, without limitation: use of a grid of lasers directlyabove the burner level to measure gas species for both tangential firedand wall fired furnace arrangements; an alternative grid design fortangential fired furnaces that can be used at each burner level or aboveeach burner level that measures gas species at a given location in theflame to control the local burner stoichiometry; ability to controllocalized combustion within the furnace using laser grid measurementthrough air flow biasing between burners as a secondary control ofcombustion; primary control of boiler combustion using lasers at thefurnace outlet to control air feeds to the burners; an improved,non-grid design to measure gas species at the flue gas outlet; controlof downstream pollution control systems using laser grid measurements;use of localized laser gas species measurements in or around the burnerarea to control the combustion and fuel air dampers for individualburner stoichiometry control; control of all boiler and environmentalcontrols using a coordinated control system having laser gas speciesmeasurements as an input; that can feedback to the control system forburner control and/or pollution control on a plant performance andeconomics basis.

The optical sources may be any lasers that transmit light in a banduseful in detecting desired constituents in the flue gasses. This mayinclude lasers of all types of gasses and species. Detection techniquesmay be based on modulation of signal frequency or signal wavelength aswell as signal attenuation. In general, embodiments of the monitoringsystem 220 include apparatus that measure gas concentrations by shiningthe laser beam through a sample of gas and measuring the amount of laserlight absorbed. However, the optical source and detector wavelengths canbe tuned to detect absorption at a variety of wavelengths. Theseproperties give laser detectors a good combination of properties,including selectivity and sensitivity.

Advantages of laser monitoring include an ability to characterize thegas constituents. That is, a tunable laser generally emits light in thenear infrared (NIR) region of the electromagnetic spectrum. Many of thecombustion gases absorb light in NIR, and may be characterized by anumber of individual “absorption lines.” A tunable laser can be tuned toselect a single absorption line of a target gas, which does not overlapwith absorption lines from any other gases. Therefore, laser gas sensingcan be considered selective with regard to sampling of gases. A varietyof other technical advantages is known to those skilled in the art.Further, tunable lasers are relatively inexpensive. Accordingly, themonitoring system 220 is cost effective and easy to maintain.

Exemplary tunable lasers are produced by Aegis Semiconductors, Inc. ofWoburn, Mass. One non-limiting example of a thermally tunable opticalfilter is disclosed in the U.S. Patent Application Publication No.:US/2005/0030628 A1, entitled “Very Low Cost Narrow Band InfraredSensor,” published Feb. 10, 2005, the disclosure of which isincorporated by reference herein in it's entirety. This applicationprovides an optical sensor for detecting a chemical in a sample regionthat includes an emitter for producing light, and for directing thelight through the sample region. The sensor also includes a detector forreceiving the light after the light passes through the sample region,and for producing a signal corresponding to the light, the detectorreceives. The sensor further includes a thermo-optic filter disposedbetween the emitter and the detector. The optical filter has a tunablepassband for selectively filtering the light from the emitter. Thepassband of the optical filter is tunable by varying a temperature ofthe optical filter. The sensor also includes a controller forcontrolling the passband of the optical filter and for receiving thedetection signal from the detector. The controller modulates thepassband of the optical filter and analyzes the detection signal todetermine whether an absorption peak of the chemical is present.

One skilled in the art will recognize that the foregoing is merely oneembodiment of the laser 221, and that a variety of other embodiments maybe practiced. Accordingly, it should be recognized that the term“optical” makes reference to any wavelength of electromagnetic radiationuseful for practice of the teachings herein. In general, theelectromagnetic radiation may include a wavelength, or band ofwavelengths that are traditionally considered to be at least one ofmicrowave, infrared, visible, ultraviolet, X-rays and gamma rays.However, in practice, the wavelength, or band of wavelengths selectedfor an optical signal are generally classified as at least one ofinfrared, visible, ultraviolet, or sub-categories thereof.

Further, one should recognize that the laser 221 generally provideslight amplification by stimulated emission of radiation. That is, atypical laser emits light in a narrow, low-divergence monochromatic beamwith a well-defined wavelength. However, such as restriction is notnecessary for practice of the teachings herein. In short, any opticalbeam that exhibits adequate properties for estimating measurement datamay be used. Determinations of adequacy may be based upon a variety offactors, including perspective of the designer, user, owner and others.Accordingly, the laser 21 need not precisely exhibit lasing behavior, astraditionally defined.

The monitoring system 220 may be provided as part of a retrofit toexisting combustion systems. For example, the monitoring system 220 maybe mounted onto existing components and integrated with existingcontrollers. Accordingly, a system making use of the teachings hereinmay also include computer software (i.e., machine readable instructionsstored on machine readable media). The software may be used as asupplement to existing controller software (and/or firmware) or as anindependent package.

Further, a kit may be provided and include all other necessarycomponents as may be needed for successful installation and operation.Example of other components include, without limitation, electricalwiring, power supplies, motor and/or manually operated valves, computerinterfaces, user displays, assorted circuitry, assorted housings,relays, transformers, and other such components.

Accordingly, provided is a combustion system that includes at least onelaser based detector at the boiler outlet to measure the gas species,such as oxygen. The purpose of both systems in both locations is, amongother things, to control the overall air flow to the boiler with thelaser at the boiler outlet and to provide a local control of the boilerburners with the use of the lasers mounted proximate to each burner.

Software may be used in the functioning and operation of various partsof the present invention. For example, electronics unit (215 of FIGS. 3,4) and control unit of FIGS. 1, 3 may employ such software. Thissoftware may be provided in conjunction with a computer readable medium,may include any type of media, such as for example, magnetic storage,optical storage, magneto-optical storage, ROM, RAM, CD ROM, flash or anyother computer readable medium, now known or unknown, that when executedcause a computer to implement the method and operate apparatus of thepresent invention. These instructions may provide for equipmentoperation, control, data collection and analysis and other functionsdeemed relevant by a user.

While the invention has been described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims.

1. A burner efficiency system (200) for adjusting the operation ofindividual burner (224) of a tangentially fired furnace (1) comprises: adetector (222) adapted to receive an optical beam (223) and for providean electrical signal corresponding to the optical beam (223) received;an optical source (221) positioned to create an optical beam (223) thatpasses through a sampling zone (8) and crosses a trajectory (42) of asingle flame emanating from an individual burner (224) and impinges uponthe detector (223); an electronics unit (214) adapted to receive thesignal created by the detector (222) and identify at least one physicalproperty of material between the optical source (221) and detector (222)and create an adjustment signal indicating parameters of said individualburner that should be adjusted to optimize the operation of thisindividual burner (224).
 2. The burner efficiency system (200) of claim1, wherein said parameters are selected from the group consisting of: asecondary air flow rate into the furnace (1), a primary air flow rateinto the furnace (1), and a fuel flow rate into the furnace (1).
 3. Theburner efficiency system (200) of claim 1, further comprising: asecondary air feed (207) for providing additional combustion air to saidfurnace (1); a control unit (214) coupled to the electronics unit (215),and to the secondary air feed adapted to adjust the amount of airprovided to the burner (224) based upon the adjustment signal providedby the electronics unit (215).
 4. The burner efficiency system (200) ofclaim 3, further comprising: a fuel feed (105) coupled to the controlunit (214), the fuel feed adapted to provide solid fuel particles to thefurnace (1); a primary air feed (206) coupled to the control unit (214),the primary air feed adapted to provide air to entrain sold fuelparticles and carry them into the furnace (1); and wherein the controlunit is further adapted to regulate the fuel feed (205) and primary airfeed (206 to adjust the amount of fuel particles and primary airprovided to furnace (1) based upon the adjustment signal received formelectronics unit (215).
 5. The burner efficiency system (200) of claim 1wherein the optical source (221) is a laser, and the detector (222) isadapted to sense laser light.
 6. The burner efficiency system (200) ofclaim 1 wherein the physical property identified comprises one of thegroup consisting of: temperature, oxygen (02) concentration, carbonmonoxide (CO) concentration, carbon dioxide (CO₂) concentration, watervapor concentration, sulfur dioxide (SO₂) concentration, sulfur trioxide(SO₃) concentration, nitrogen dioxide (NO₂) concentration, nitrogentrioxide (NO₃) concentration, mercury (Hg) concentration, unburnedhydrocarbon concentration and unburned fuel concentration.
 7. The burnerefficiency system (200) of claim 1 wherein the optical beam (223)crosses the flame trajectory (42) an intersection point (45).
 8. Theburner efficiency system (200) of claim 1 wherein the distance from theintersection point 45 to its corresponding burner (224) is the same forall burners (224).
 9. The burner efficiency system (200) of claim 1wherein there are a plurality of burners (224) on multiple levels offurnace 1, and there is a plurality of an optical sources (221) eachpositioned to create an optical beam (223) crosses a trajectory (42) ofa flame emanating from a single burner (224) and impinges upon adetector (223).
 10. An apparatus (200) for monitoring a property of atleast one constituent in flue gas from a furnace (1), the apparatuscomprising: an optical monitoring system (220) comprising at least oneoptical source (221) adapted to provide an optical beam (223) throughflue gasses substantially produced by a single burner (224) of a furnace(1), and at least one detector (222) adapted to detect the optical beam(223) and provide a monitored signal to an electronics unit (215), theelectronics unit (215) configured to estimate a property of at least oneconstituent in the sampling zone and create an adjustment signal toadjust the operation of said furnace (1).
 11. The apparatus (200) as inclaim 10, wherein the at least one laser (121) comprises a semiconductortunable optical laser.
 12. The apparatus (200) as in claim 10, whereinthe constituent comprises at least one of CO, CO₂, Hg, SO₂, SO₃, NO_(x),O₂, Hg and unburned fuel.
 13. The apparatus (200) as in claim 10,wherein the property comprises at least one of a presence, a quantity, adensity, a concentration of said constituent and a rate of change of anyof these properties.
 14. The apparatus (200) as in claim 10, furthercomprising a control unit (214) adapted to receive the adjustment signaland control the furnace (1).
 15. The apparatus (200) as in claim 14,wherein the control unit (214) is configured to control a flow of atleast one of a fuel feed (205), a primary air feed (206) and a secondaryair feed (207) to said furnace (1).
 16. The apparatus (200) as in claim10, comprising a plurality of lasers (221) for providing a plurality ofbeams (223) and a plurality of detectors (222) for detecting theplurality of beams (223).
 17. The apparatus (200) as in claim 10,wherein the plurality of lasers (221) and the plurality of detectors(222) are arranged for monitoring a tangentially-fired furnace (1). 18.The apparatus (200) as in claim 10, wherein the electronics unit (215)comprises machine executable instructions stored on machine-readablemedia, the instructions comprising instructions for: estimating aproperty of the at least one constituent; determining an adjustmentsignal from the estimated property to cause the estimated property tobecome closer to a predetermined value; and providing an adjustmentsignal to the control unit (214).
 19. The apparatus (200) as in claim18, further comprising instructions for modulating the optical signal.20. The apparatus (200) as in claim 10, wherein the beams (223) passthrough two or three dimensions of the combustion system (1).
 21. Amethod for adjusting the operation of individual burner (224) of atangentially fired furnace (1) comprising the steps of: creating anoptical beam (223) that passes through a sampling zone (8) and crosses atrajectory (42) of a flame emanating from an individual burner (224) andimpinges upon a detector (223); sensing the optical beam (223) at thedetector; creating an electrical signal corresponding to the sensedoptical beam (223); identifying at least one physical property ofmaterial in the sampling zone (8) from the created electrical signal;comparing the identified physical properties to a predetermined desiredlevel; calculating adjustments of a set of burner parameters that wouldcause the identified physical property to adjust toward thepredetermined desired level; adjusting the burner parameters of theindividual burner according to the calculated adjustments to optimizethe operation of the individual burner (224).
 22. The method as in claim21, wherein at least one of the identifying and the adjusting isperformed on a real-time basis.